Originální popis anglicky: fegetround, fesetround - get and set current rounding direction

Návod, kniha: POSIX Programmer's Manual

STRUČNĚ

#include <fenv.h>

int fegetround(void);

int fesetround(int round);

POPIS / INSTRUKCE

The fegetround() function shall get the current rounding direction.

The fesetround() function shall establish the rounding direction represented by its argument round. If the argument is not equal to the value of a rounding direction macro, the rounding direction is not changed.

NÁVRATOVÁ HODNOTA

The fegetround() function shall return the value of the rounding direction macro representing the current rounding direction or a negative value if there is no such rounding direction macro or the current rounding direction is not determinable.

The fesetround() function shall return a zero value if and only if the requested rounding direction was established.

CHYBY / ERRORY

No errors are defined.

The following sections are informative.

PŘÍKLADY POUŽITÍ

The following example saves, sets, and restores the rounding direction, reporting an error and aborting if setting the rounding direction fails:


#include <fenv.h>
#include <assert.h>
void f(int round_dir)
{
    #pragma STDC FENV_ACCESS ON
    int save_round;
    int setround_ok;
    save_round = fegetround();
    setround_ok = fesetround(round_dir);
    assert(setround_ok == 0);
    /* ... */
    fesetround(save_round);
    /* ... */
}

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SOUVISEJÍCÍ

The Base Definitions volume of IEEE Std 1003.1-2001, <fenv.h>

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

2003	IEEE/The Open Group